Field of the Invention
The invention relates to the field of space vehicles, and more particularly the field of satellites intended for placing into orbit.
Description of the Related Art
A satellite conventionally comprises a body forming a support for the items of equipment of the satellite. The items of equipment can be divided into two categories. The first category is called the payload and comprises the main instrument of the mission as well as the electronic devices necessary for its correct operation. It is for example an optical instrument, in the case of a mission intended for collecting images and optical measurements, or one or more antennas in the case of telecommunication satellites. The second category comprises items of equipment denoted in the present application as secondary, intended for the general operation of the satellite such as thrusters, receiving antennas, tanks or solar panels as well as electronic devices ensuring the control and command of these ancillaries.
The launch of a satellite for placing into orbit is conventionally carried out using a launcher in which the satellite is placed. The launcher comprises propulsion means allowing it to reach the intended destination and to release the satellite there.
In order to reduce costs, it is known to use one launcher for placing several satellites into orbit, during the course of one and the same launch. This is then referred to as multiple launch.
The problems to be solved are, in particular, holding the satellites in the launcher and storing them in the nosecone.
In fact, during the launch, then at the time of release, the satellites are subjected to impacts and vibrations transmitted from the launcher to the satellites. The arrangement of the satellites in the launcher must therefore avoid the impacts and vibrations propagating excessively in the satellites and damaging the items of equipment while ensuring good mechanical strength of all of the satellites in the launcher.
A known solution for a multiple launch consists of connecting the satellites to a central structure of the launcher, called a dispenser, which forms housings in which the satellites are placed. Document U.S. Pat. No. 8,939,409 describes an example dispenser. A dispenser typically comprises on the one hand components fixed to the launcher and optionally on the other hand components fixed to the satellites, i.e. on the one hand interface components intended to remain in the launcher after releasing the satellites, and on the other hand interface components intended to accompany the released satellites. The satellites are thus supported by the dispenser in the manner of a set of shelves, and do not support one another. However, such a structure is bulky and is only suitable for satellites of small dimensions, or limits the number of satellites capable of being installed in the launcher due to the size of the nosecone. Moreover, it constitutes an increase in the weight of the launcher, while being unnecessary for the mission.
Another solution then consists of stacking the satellites one on top of another providing, on the actual structure of each satellite, a dedicated interface for the stack.
Document U.S. Pat. No. 8,511,617 (corresponding to US patent application 2009/224105) proposes an example satellite stack having a dedicated interface structure. In this document, the dedicated structure is in the form of an outer cylinder, the cylinders then serving as a path for the transmission of the loads when the satellites are stacked. The diameter of the cylinder of a satellite is comprised in this document between 2 m and 5 m.
A drawback of the structure is that it has a significant diameter compared to the standard launcher interface diameters in the space field. In fact, in order to fit a satellite into a launcher, the latter comprises a satellite interface ring on which the satellite is fixed. So that the launcher is compatible with several satellites, it is known for the satellite interface ring of the launcher to have a standard diameter, selected from 937 mm (millimetres), 1194 mm and 1666 mm. Consequently, the dedicated structure described in U.S. Pat. No. 8,511,617 cannot be mounted directly on the satellite interface ring of the launcher, but an intermediate support must be placed between the satellite and the ring of the launcher in order to make the connection between the two diameters. Moreover, the diameter of the dedicated structure is greater than the largest of the standard diameters, filling almost all of the space below the nosecone of the launcher, so that all of the items of equipment of the satellite are located inside the cylinder of the dedicated structure.
EP 2202553 discloses a space telescope, and US 2012/154585 relates to an integrated microsatellite antenna system.
Consequently, there is a need for a novel satellite having a structure making it possible in particular to overcome the aforementioned drawbacks.